Plasmaspheric Shoulder Due to Penetration E-field
- IMAGE Extreme Ultraviolet (EUV) observed shoulder-shaped bulge in
morning sector plasmapause [May 24, 2000, 6-10 UT ]
- Magnetospheric Specification Model (MSM) reproduces shoulder, provides
physical explanation:
- Sudden, strong northward turnings of IMF Bz (3:45 and 4:30 UT)
trigger strong penetration electric field in plamasphere.
- Penetration E-field pushes out pre-dawn plasma, forming shoulder.
ABOVE: Wind spacecraft IMF data. Northward turnings at ~3:45 UT and 4:30
UT on May 24. EUV first saw shoulder 6:03 UT.
LEFT: Snapshot from EUV imager, 7:04 UT. Morning sector
plasmaspheric shoulder first observed at 6 UT, but formed
earlier.
RIGHT: Snapshot from MSM simulation, 7:00 UT. Model captured
formation and time evolution of shoulder, 4-10 UT.